The present invention relates generally to protective head gear and, in several embodiments, to protective helmets including a force attenuation liner or impact cap to which a structural mount for a visor is operatively connected.
The following information is provided to assist the reader in understanding the invention disclosed below and the environment in which it will typically be used. The terms used herein are not intended to be limited to any particular narrow interpretation unless clearly stated otherwise in this document. References set forth herein may facilitate understanding of the present invention or the background of the present invention. The disclosure of all references cited herein are incorporated by reference.
Protective head gear is used or should be used in numerous activities in which the head can be impacted, including, but not limited to, sports activities, recreational activities, vehicular operation, work activities in hazardous industrial environments, military operations, aviation, and fire fighting. Such protective head gear typically includes a rigid outer shell of metal or plastic and a suspension system to support the shell on the wearer's head. The rigid outer shell prevents an impacting object from contacting the head and the suspension system operates to attenuate and distribute impact forces transferred to the head.
Impact attenuating suspensions can, for example, include a web of straps attached to the shell and arranged as a cradle over the top of the wearer's head or a compressible foam liner positioned between the wearer's head and the interior of the shell.
U.S. Pat. No. 4,286,339, assigned to the assignee of the present invention, the disclosure of which is incorporated herein by reference, discloses a protective helmet, such as firefighter helmet, which combines aspects of a web suspension with aspects of a foam liner suspension. A chinstrap for the helmet assembly of U.S. Pat. No. 4,286,339 is rigidly affixed to the outer shell to retain the protective helmet on the head. Fixing the chinstrap to the outer shell in an unyielding manner, however, can potentially place too much force on the wearer's neck under certain circumstances (for example, during a fall through a floor in the case where the helmet impacts an object or becomes stuck).
To reduce the likelihood of placing excessive force on the neck, a number of protective helmets have included a chinstrap assembly that is releasably attached to the protective helmet assembly. Typically, detachment of the entire protective helmet assembly from the user left the user's head completely unprotected against subsequent impacts with an object or against a stationary object.
U.S. Pat. No. 5,044,016, assigned to the assignee of the present invention, the disclosure of which is incorporated herein by reference, describes a helmet assembly including an outer shell and an inner impact attenuation liner assembly. A chinstrap assembly is mounted to the inner impact attenuation liner assembly and the inner impact attenuation liner assembly is mounted within the outer impact shell such that it detaches under predetermined load conditions from the outer impact shell. After separation of the inner liner assembly from the outer shell, the inner liner assembly remains on the user's head. The inner liner assembly thus continues to provide the user with some protection from subsequent impacts.
Although significant improvements have been made in protective helmets, it remains desirable to develop improved protective head gear.